1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly to estimating available bandwidth in a wireless network.
2. Background
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency divisional multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level.
An example of a telecommunication standard is Universal Mobile Telecommunications System (UMTS). UMTS is a third generation mobile cellular system for networks based on the Global System for Mobile Communications (GSM) standard. UMTS was developed and maintained by the 3rd Generation Partnership Project (3GPP), and is a component of the International Telecommunications Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators. UMTS specifies a complete network system which uses, covering the radio access network (UMTS Terrestrial Radio Access Network, or UTRAN), the core network (Mobile Application Part, or MAP) and the authentication of users via SIM (subscriber identity module cards).
Another example of a telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the UMTS mobile standard promulgated by Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
Mobile terminals, or user equipment (UE), can communicate with one or more base stations in an active communication mode, or a more conservative communication mode, such as idle mode where the UE powers down its transceiver during some time intervals to save power. In idle mode, for example, the UE can power up its transceiver during defined paging intervals to receive paging signals from the base station(s), or to establish an active communication mode connection with the base station(s). The UE can switch communications among base stations when in an active mode, e.g., via a handover process, or when in an idle mode, e.g., via a cell reselection procedure. Selection or reselection of base stations or related cells is typically based on a signal strength in a candidate cell; however, with the addition of user-deployable base stations (e.g., femto nodes, pico nodes, or the like), there can be multiple cells with sufficient signal strength to adequately serve a UE. In addition, a UE may obtain wireless services by communicating with a network (e.g., UMTS or LTE) or a nearby wireless local area network (e.g., WiFi). In some instances, LTE and/or UMTS may prove to be a better network (e.g., it may provide service to a UE that is faster, with greater bandwidth, providing greater throughput, or some other quality measurement), while in other instances, or at other times, WiFi may prove to be the better network.
As such, it is desirable to determine metrics that may allow a UE to select the better network as between LTE and/or UMTS and WiFi at a given point in time.